819563440 has 40 divisors (see below), whose sum is σ = 1946036160. Its totient is φ = 320848896.

The previous prime is 819563419. The next prime is 819563441. The reversal of 819563440 is 44365918.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 819563393 and 819563402.

It is not an unprimeable number, because it can be changed into a prime (819563441) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 105225 + ... + 112744.

It is an arithmetic number, because the mean of its divisors is an integer number (48650904).

Almost surely, 2^819563440 is an apocalyptic number.

819563440 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

819563440 is an abundant number, since it is smaller than the sum of its proper divisors (1126472720).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

819563440 is a wasteful number, since it uses less digits than its factorization.

819563440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 218029 (or 218023 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 40.

The square root of 819563440 is about 28628.0184434760. The cubic root of 819563440 is about 935.8240288177.

The spelling of 819563440 in words is "eight hundred nineteen million, five hundred sixty-three thousand, four hundred forty".